Bulletin of the National Research Centre (Feb 2021)
Genetic variability and association between oil and economic traits for some new Egyptian cotton genotypes
Abstract
Abstract Background Cotton breeding programs mainly focus on improving cotton fibers, but less attention has been paid by breeders to cottonseed oil improvement. Breeding cottonseed for oil content has mainly depended on phenotypic information used to select varieties with high seed oil content. The purpose of this study was to evaluate some cotton genotypes regarding their oil content and other characters related to fiber yield, in order to select genotypes with high oil content and acceptable levels of the other characters. Seventeen different genotypes of cotton were used in this study. A two-year experiment was carried out at Sids Agricultural Research Station, Beni Suef, Egypt, during 2017 and 2018, using a randomized complete block design with six replications. Seed cotton yield, lint cotton yield, boll weight, seed index, embryo index, oil % and embryo oil index characters were recorded. Results The analysis of variance results showed highly significant differences among the genotypes for all the studied traits except boll weight in season 2017. The overall cotton embryo oil % ranged from 33.40 to 40.28 among the genotypes, while the overall cotton embryo oil index ranged from 1.79 to 2.47. Maximum cotton embryo oil % was noted by the genotypes 15 [{(G83 × G80) × G89} × Australian] and 8 [(G 91 × G90) × (G 85 × G 83)], while maximum cotton embryo oil index was noted by the genotype 13 [(G 91 × G 90) × G80]. The results showed positive correlations between seed cotton yield and lint cotton yield, seed index and embryo index, seed index and embryo index oil %, embryo index and embryo index oil %, and oil % and embryo index oil %. Conclusions It could be concluded that using seed or embryo oil percentages as criteria for differentiating genotypes according to their oil content is misleading and the best efficient measure is using the seed or embryo oil indices because they depend on weight basis. Also, Genotypes 13, 15 and 8 were the best genotypes regarding oil % and they could be used in breeding programs for cotton oil improvement.
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